Conventionally, for integrated circuit designing, the characteristics of circuit elements (circuits) for use in an integrated circuit have to be taken into consideration. Although the characteristics of the circuit elements under specific conditions are provided on an attached data sheet or cell characteristic table, the use conditions of the circuit elements for use in an actual integrated circuit may vary, and therefore only the characteristics of the circuit elements under the specific condition are insufficient.
For this reason, to obtain the characteristic of the circuit element under various conditions, users have to use analysis information, such as Simulation Program with Integrated Circuit Emphasis (SPICE), or Input/Output Buffer Information Specification (IBIS) of a simulation model to input operation conditions and analyze the circuit element.
In one known technology, a circuit element varied with variations of manufacturing conditions and its circuit-element value are combined together based on a design of experiment to minimize the number of times of analysis. In another known technology, a batch job is generated and executed with a model-parameter extracting procedure and a conditioned set of model parameters to reduce computer use cost.
Examples of the conventional technologies are disclosed in Japanese Laid-open Patent Publication No. 05-266119 and Japanese Laid-open Patent Publication No. 11-250033.
However, to analyze the characteristic of a circuit element under a non-specific condition by using SPICE/IBIS, expertise in description and operation of SPICE/IBIS is required. Therefore, people other than users with such expertise cannot easily obtain the characteristic of the circuit element under the non-specific condition.